Background: Lactic acid bacteria serve as the starter of food fermentation. They improve food taste and inhibit the growth of organisms. Bacteriocin is a major natural inhibitor produced by Lactobacillus plantarum.

Materials and Methods: For this exploratory study, we have purchased some hotdog and sausage made by different factories. Having one gram of sausage or hotdog in physiologic serum, it was diluted and cultured in MRS media. Bacteria growth was surveyed in different PH, temperature and media.

Results: Of 15 samples, Lactobacillus plantarum was isolated in 4. Its optimal condition was as below: Temperature 25 degrees centigrade, pH=4.8-6.4 and basic MRS media with glucose 2%. Its antimicrobial activity was reserved in 100 degrees centigrade for 10 minutes and has not modified by alpha amylase or lysosomes. At 25 degrees centigrade, they had maximum inhibitory effect on staphylococcus (20ml) and listeria (14ml).

Conclusion: The stability of Lactobacillus plantarum’s antimicrobial activity against high temperature is of utmost importance since during food processing we require high temperature. We suggest the usage of suitable starter media to produce strong antimicrobial agents in fermentative foods. Employing genetic changes may be helpful to produce Lactobacilli with potentially greater bacteriocin production